Computed tomography (CT) and various, other medical imaging techniques have been used to detect cancer in patients. CT images, for example, allow medical personnel to screen for tissue anomalies, classifying them based on indicators such as abnormal or normal, lesion or non-lesion, and malignant or benign. Conventional CT image analysis and interpretation and cancer detection and diagnosis techniques involve a radiologist assessing volumes of CT image data of a subject tissue. Given the volume of data, however, it can be difficult to identify and fully assess CT image data for cancer detection. CT image analysis is known to result in mis-diagnoses in some instances, resulting from false positive determinations that lower overall efficiency of CT image analysis as a viable detection technique. There are automated techniques for CT image analysis, e.g., automated techniques for detecting lung nodules in CT scans. Yet, these automated techniques are nonetheless limited and, as with non-automated techniques, are benefited by using higher dose CT imaging for data collection for better image quality.
For CT image analysis, interpretation, detection and diagnosis, there is a tradeoff between radiation dosage levels and image quality. Generally, higher radiation doses result in higher signal-to-noise ratio, higher resolution images with fewer artifacts, while lower doses lead to increased image noise, more artifacts and less-sharp images. The higher radiation may, though, increase the risk of adverse side effects, e.g., increasing the risk of radiation-induced cancer. As a result, low dose radiation CT has been studied of late, with the hope of improving image analysis and detection, without increasing the chances of potential adverse side effects.
Yet, despite recent developments in radiation dose reduction techniques in CT scanning, e.g., techniques such as adaptive exposure and iterative reconstruction, current radiation dosing is still very high, especially for screening populations. As such, there continues to be public concern about radiation risks from current CT testing levels. In response, the techniques of the present invention provide a way of using low-dose CT imaging with vastly improved, higher-dose like image quality.